edit /etc/spamassassin/local.cf for global rules.

Body checks:

body JUSTHEALTHY          /www\.mb103\.com/
score JUSTHEALTHY 3.0
describe JUSTHEALTHY     Spammer address detected in body

Header checks:

header MONEY_BAG          Subject =~ /💰/
 
header BITCOIN_INVESTOR_LIST       List-Unsubscribe =~ /bitcoin-investor\.ml/
score BITCOIN_INVESTOR_LIST 3.0
describe BITCOIN_INVESTOR_LIST     List-Unsubscribe contains known spammer

Recommendation: add rules into ~/.spamassassin/user_prefs then test with a .eml file. They can then be moved into /etc/spamassassin/local.cf

Check your local.cf syntax by typing:

spamassassin --lint

To test an email (get the header report out):

spamassassin -t someemail.eml

Test an email with:

spamassassin < someemail.eml

From the command line, you can make sure spamassassin works by trying:

spamassassin -D </usr/share/spamassassin/doc/spamassassin-3.0.3/sample-spam.txt